Impact of a Changing Population Structure and Clustering of Cancer in Prostate Cancer Patients Depending on a First-Degree Family History

Introduction: In the last century, there have been major changes within the population structure in Germany. The aim of this study was to determine the impact of a changing population structure on identification of familial prostate cancer (PCa), and to investigate how many and which types of other cancers have occurred in patients and their first-degree relatives. Materials and Methods: A total of 19,540 patients were evaluated in a prospectively collected PCa family database and divided into four birth cohorts: 1925-1934 (cohort A), 1935-1944 (cohort B), 1945-1954 (cohort C), and 1955-1964 (cohort D). Other primary cancers and cancers of first-degree relatives were evaluated. Results: The percentage of PCa patients with ≥2 sons declined (A: 28.9% to D: 21.6%). The percentage of patients whose fathers lived for ≥65 years increased (B: 64.2% to D: 73.0%). Malignancies of the skin, the urinary tract, and the lymphoid/hematopoietic tissue were more common in patients with a positive first-degree PCa family history and their first-degree relatives. Additionally, first-degree relatives reported more often neoplasms of respiratory/intrathoracic organs and the female breast. Conclusions: A small family size, an early deceased father, and a high number of sporadic cases complicate the identification of familial PCa patients. Thus, a detailed family history should also include unaffected first-degree relatives to avoid any misclassification. Findings of other primary cancers in patients and their relatives warrant further investigation.